//封装倒计时逻辑函数
import { ref } from 'vue'
import dayjs from 'dayjs'
import {computed, onUnmounted} from 'vue'

export const useCountDown = () => {
  let timer = null
  const time = ref(0)
  //格式化时间
  const formatTime = computed(() => {
    return dayjs.unix(time.value).format('mm分ss秒')
  })
  //开启倒计时
  const start = (currentTime) => {
      time.value = currentTime
     timer =  setInterval(() => {
        time.value--
      }, 1000)
  }
  //组件销毁时清除定时器
  onUnmounted(() => {
   timer && clearInterval(timer)
  })
  return {
    formatTime,
    start
  }
}
